
Federal law defines nine categories that would legally prevent a person from owning a gun, which include being convicted of a felony, a misdemeanor domestic violence charge, being adjudicated as a “mental defect” or committed to a mental institution, the subject of a restraining order or having an active warrant. Online court records show Ator was arrested in 2001 for a misdemeanor offense that would not have prevented him from legally purchasing firearms in Texas.

Wester did not say when Ator failed the background check or why. Authorities have not said how Ator obtained the gun used in the shooting, but Ator had previously failed a federal background check for a firearm, said John Wester, an agent with the federal Bureau of Alcohol, Tobacco and Firearms. The daylight attack over the Labor Day holiday weekend came just weeks after another mass shooting killed 22 people in the Texas border city of El Paso. “He was not nice, he was not friendly, he was not polite.”

“We were afraid of him because you could tell what kind of person he was just by looking at him,” Gutierrez said.